The purpose of this research is to better understand the relationships of genetic control, molecular structure, and function of hemoglobins of humans and other animals. Current work includes structural characterization of abnormal human hemoglobins, sequence analysis of the zeta chain of the embryonic hemoglobin Portland 1, and comparisons of selected animal hemoglobins with those already known. Parallel studies of the functional properties of abnormal human hemoglobins are being done in order to map the functionally important residues of the molecule. Special emphasis is placed on comparisons of functional properties of mutant hemoglobins with different substitutions at the same residue position in order to better understand specific properties of functionally critical residues.